JPH0584392A - Washing machine - Google Patents

Abstract

PURPOSE:To cope with intense stains and shorten the washing time by applying strong force to the laundry. CONSTITUTION:A brushless DC motor 8 rotating a rotary vane 7, an inverter circuit 20 driving the brushless DC motor 8, and a control circuit 30 controlling the inverter circuit 20 to repeat the positive rotation and reverse rotation of the rotary vane 7 with no stop period afforded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine, and more particularly to control of rotary blades.

[0002]

2. Description of the Related Art Some conventional washing machines use a condenser motor to drive a rotary wing (pulsator).
However, since the starting torque of the capacitor motor is weak, it is difficult to reverse it suddenly, and the rotation direction is always changed with the stop state in between. As a result, since the direction of the water flow is changed after the water flow caused by the rotor blades weakens, it cannot produce a strong change in the water flow and is not suitable for removing strong dirt. Also, since there is a stoppage time, the washing time was lengthened accordingly.

[0003]

Conventionally, since a condenser motor having a small starting torque was used to drive the rotor blade, the motor was not rapidly reversed. For this reason,
There was a period of suspension in the rotor blades, the force of the water flow generated by the rotor blades could not be used effectively, and it was not suitable for removing strong dirt. In addition, the washing time was extended by the amount of the suspension period.

Therefore, according to the present invention, a stronger force can be applied to the laundry and it is possible to cope with strong stains.
Moreover, it aims at providing the washing machine which can shorten a washing time.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a rotor for generating a washing water flow, a brushless DC motor for rotating the rotor, and a brushless D.
The gist of the present invention is to have an inverter circuit that drives a C motor and a control circuit that controls the inverter circuit to repeat normal rotation and inversion without giving a stop period to the rotor.

[0006]

By rotating the rotary blades in the normal rotation and the reverse rotation without a stop period, a larger acceleration, that is, a force, is applied to the laundry than before. As a result, a strong twisting force is applied to the laundry and it is possible to deal with strong dirt.
Further, since there is no stop period, the washing time is shortened accordingly.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall schematic structure of a washing machine. In the figure, 1 is a main body of a washing machine, 2 is a washing tub elastically suspended by a suspension 4 (hereinafter, also referred to as an outer tub), 3 is a washing tub that also serves as a dehydrating tub for washing and dehydrating clothes as laundry ( Hereinafter, also referred to as an inner tank), a large number of holes 5 for draining water are formed on the side surface of the peripheral wall thereof, and a fluid balancer 6 is provided on the upper portion thereof. At the bottom of the inner tub 3, a pulsator (rotary blade) 7 for generating a washing water flow is provided. The pulsator 7 is rotated by a brushless DC motor 8 via a belt 9 and a mechanical case 10 containing a brake and a clutch mechanism.

At the top of the washing machine body 1, a water supply hose 11 is provided.
A detergent dissolving device 12 connected to is installed. The detergent is dissolved in advance by the detergent dissolving device 12 before the washing process, and water is supplied to the washing tubs 2 and 3 together with the dissolved detergent. On the other hand, a drain hose 14 having a drain valve 13 is attached to the bottom of the outer tub 2. The drain valve 13 is closed during the washing process, the water supplying process, and the rinsing process. In addition, an electronic circuit unit 15 having a microcomputer, an inverter circuit, a control circuit, etc. described below is installed on the upper part of the washing machine body 1.

FIG. 2 shows the inverter circuit 20, the motor control circuit 30 and the like.

As the brushless DC motor 8, one having a general three-phase armature winding u, v, w is used, and the inverter circuit 20 for driving the brushless DC motor 8 has all three phases. A wave bridge type inverter is used. In the inverter circuit 20, 22 is a diode bridge for rectification, and 3 is a smoothing capacitor. After the AC voltage from the commercial AC power supply 21 is rectified by the diode bridge 22, it is smoothed by the capacitor 23 to obtain a DC voltage. It is designed to be used. Then, this DC voltage is converted into a three-phase AC at a three-phase full-wave bridge portion composed of six transistors as switching elements. That is, in the three-phase full-wave bridge portion, six transistors u ₁ , u ₂ , v ₁ , v ₂ , w ₁ and W ₂ are connected to three pairs of arms corresponding to the three phases. .. Hereinafter, for convenience of explanation, the three arms on the side to which the transistors u ₁ , v ₁ and w ₁ are connected are referred to as the upper arm and the three arms on the other side to which the other transistors u ₂ , v ₂ and w ₂ are connected. The lower arm. Three connection points of the upper arm and the lower arm are connected to the three-phase armature windings u, v, w in the brushless DC motor 8.

The brushless DC motor 8 includes, in addition to the armature windings u, v, and w, a rotor (not shown) formed of permanent magnets, and three Hall ICs for detecting the rotational position of the rotor. Is provided. Reference numeral 24 is a signal output line of a rotor position detection signal from the Hall IC, that is, a Hall IC signal, and the Hall IC signal is given to the motor control circuit 30.

The motor control circuit 30 is provided with a Hall IC signal synthesis circuit 25, a start / stop circuit 26 and a current protection circuit 27. Hall IC synthesis circuit 25
Is a Hall IC which is a detection signal of the rotor position of the brushless DC motor 8 in response to the forward / reverse signal from the microcomputer.
In order to combine the signals and to rotate them in the normal or reverse direction, it is determined in which direction the armature windings u, v, w should be excited, and for that purpose, which transistor in the inverter circuit 20 should be turned on. .. Start / stop circuit 26
Receives a start / stop signal from the microcomputer and outputs a signal for starting or stopping the brushless DC motor 8 to the inverter circuit 20. The current protection circuit 27 has a function of turning off all the transistors for transistor protection when the inverter current value detected by the resistor 29 exceeds a certain value. 28a-2
8f is a drive circuit, the transistors u ₁ to w ₂ of the inverter circuit 20 is driven by circuit 28a~28f in accordance with the instruction of the motor control circuit 30, on, and is turned off controlled.

In the above-mentioned structure, the microcomputer can normally / rotate the motor control circuit 30 without giving a stop signal.
By supplying the reversal signal, the brushless DC motor 8 having a large starting torque is rapidly reversed, and the pulsator 7 can repeat normal rotation and reverse rotation without a stop period. At this time, the transistors in the inverter circuit 20 are turned on and off as shown in FIG. That is, the transistors u ₁ and w ₂ are turned on, and then the transistors w ₁ and u ₂ are turned on without a stop period. When such a rapid reversal is performed, the brushless DC motor 8
A large torque may be applied to the inverter and a large inverter current may flow. Against this, the current protection circuit 27 protects the transistors u _{1 to} w ₂ .

FIG. 4 shows changes in the rotation speed and the angular acceleration of the pulsator 7 when the forward rotation and the reverse rotation are repeated in this manner. FIG. 5 shows, as a comparative example, changes in rotational speed and angular acceleration in the conventional example. 4 and 5
In comparison, the angular acceleration in this embodiment is larger than that in the conventional example. Since the acceleration is proportional to the force, a larger force can be applied to the laundry by this embodiment, and a stronger stain can be dealt with. Further, since the pulsator 7 is not stopped, the washing time is shortened by this amount.

[0016]

As described above, according to the present invention,
Since the normal rotation and reversal are repeated without giving a stop period to the rotor blade, it is possible to apply a stronger force to the laundry and to cope with strong dirt, and also to shorten the washing time. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a washing machine according to the present invention.

FIG. 2 is a diagram showing a circuit configuration of this embodiment.

FIG. 3 is a diagram showing an operation example of a transistor in an inverter circuit in this embodiment.

FIG. 4 is a waveform diagram showing changes in rotation speed and angular acceleration of the pulsator in the present embodiment.

FIG. 5 is a waveform diagram showing changes in rotation speed and angular acceleration of a pulsator in a conventional example.

[Explanation of symbols]

 7 Pulsator (Rotary blade) 8 Brushless DC motor 20 Inverter circuit 30 Motor control circuit

Claims (1)

[Claims] 1. A rotary vane for generating a washing water flow, a brushless DC motor for rotating the rotary vane, an inverter circuit for driving the brushless DC motor, and a stop period for the rotary vane by controlling the inverter circuit. A washing machine having a control circuit that repeats normal rotation and reverse rotation without giving.